Valve block with spring-loaded valves

ABSTRACT

A valve block, particularly suitable for controlling hydraulically powered self-advacing mine roof supports comprises at least one pair of valve consisting of an inlet valve normally urged into closed position by a spring, and an outlet valve, normally urged into open position by a spring, the valves being suitable for association with pairs of conventional spring-urged valves, i.e., both inlet and outlet normally closed and cam means operable on the valves such that the valves may or may not be moved into a set position.

United States Patent [72] lnventor David B. Smith Sheffield, England121] App]. No. 770,534 [221 Filed Oct. 25, 1968 [45] Patented Jan. 26,1971 [73] Assignee A. G. Wild & Co. Limited [32] Priority Oct. 27, 1967[33] Great Britain 1 3 1 48958/67 [54] VALVE BLOCK WITH SPRING-LOADEDVALVES 7 Claims, 7 Drawing Figs.

[52] U.S.Cl 137/596.l, 251/251; 137/636.1 [51] Int.Cl ..Fl6k 11/10, F16k31/524 [50] Field of Search 137/5961, 596.2, 627.5, 595, 636, 607;251/251 [56] References Cited UNITED STATES PATENTS 2,337,659 12/1943Hughey et al 137/595X 2,647,536 8/1953 Lunde 137/636 2,498,121 2/1950Haberlancl.... 137/596. 1X 2,726,680 12/1955 Baines 137/596.1X 3,099,4617/1963 Stelzer 137/596.1X 3,107,694 10/1963 Hastings et al 137/596.1XFOREIGN PATENTS 318,937 1/1932 Canada. 400,344 1941 Canada. 410,1741/1943 Canada. 428,223 6/1945 Canada. 538,986 4/1957 Canada.

Primary Examinerl-1enry T. Klinksiek Attorney-Lowe and King ABSTRACT: Avalve block, particularly suitable for controlling hydraulically poweredself-advancing mine roof supports comprises at least one pair of valveconsisting of an inlet valve normally urged into closed position by aspring, and an outlet valve, normally urged into open position by aspring, the valves being suitable for association with pairs ofconventional spring-urged valves, i.e., both inlet and outlet normallyclosed and cam means operable on the valves such that the valves may ormay not be moved into a set position.

PATENTED JAN26 I971 SHEET 1 [IF 4 Afro/MEX;

VALVE BLOCK WITH SPRING-LOADED VALVES This invention relates to a valveblock particularly adapted for controlling powered advancing undergroundmine roof supports.

Such supports normally comprise a pair of fluid-operable chocks joinedby roof and floor bars and one or more doubleacting rams by which thesupport can be advanced towards a mine face conveyor and the latter canbe advanced towards the mineral (e.g. coal) face.

According to the invention, a valve block, comprises at least one pairof inlet and exhaust valves, the inlet valve being normally closed underthe action of a spring, and the exhaust valve being normally open underthe action of a spring, both valves being displaceable against theirrespective springs by cam means.

When considering the application of the above-defined valve block to apowered mine roof support, the valves defined therein are suitable forcontrolling the usual doubleacting advancing ram, one pair of valvescontrolling the push" side of the ram and a second pair of valvescontrolling the pull side of the valve. Pairs of conventional valvesi.e. both being normally closed may also be incorporated into the valveblock, a first pair to control the forward chock and a second pair tocontrol the rear chock. Thus for a powered sup port consisting of oneforward and one rear chock four pairs of valves are required in thevalve block. For a support having one forward and two rear checks, allin line, a further pair of valves for controlling the third chock isrequired. Again, a further pair of valves may be required to controlsome auxiliary equipment e.g. an advanceable forward cantileverextension of the roof support, but whatever number of pairs of valvesare required, all may be provided in a single unitary valve block, oralternatively, each pair may be provided in a separate section of valveblock, the various sections being secured together to form the valveblock proper and hence to provide a valve block capable of being builtup, or reduced, to suit a particular hydraulic circuit or particularoperating conditions.

Each valve includes, of course, a valve member and a valve seat.

However, an important inventive feature is that the valve membersaccording to the invention i.e. those which control the double-actingram or rams are such as to assume a neutralfree position, that is,because the exhaust valve is normally open they permit fluid to befreely vented from either end of the ram concerned and thus permit theram piston rod to be moved in or out without any substantial resistance.A valve block so constructed may be employed in the system disclosed inUS. Pat. Application Ser. No. 800,663, filed Feb. 19, 1969, titledCONTROL OF MINE ROOF SUPPORT ASSEM- BLY" and assigned to the sameassignee as the present application.

The exhaust valve may be displaced against its spring by means of a cam,the axis of rotation of which is fixed, with seating of the valveensured by having a floating valve seat, also movable against springaction, so that manufacturing tolerances and wear have no adverse effecton seating of this valve.

Alternatively, the exhaust valve may be displaced into seatingengagement with a fixed valve seat by means of a cam pivoted slightlytowards the exhaust valve, with the exhaust valve spring lighter thanthe inlet valve spring, the cam acting through a loose thrust plate ontoboth the inlet and exhaust valve members. When the cam is rotated, itsdisplaced axis of rotation and the different spring ratings mean thatthe end of the plate contacting the exhaust valve member is displaced before the end of the plate contacting the inlet valve, the latter end ofthe thrust plate only being displaceable when the exhaust valve end isarrested by seating of the exhaust valve member. Then, the thrust plate,under the force put on it by the cam, pivots about its point of contactwith the exhaust valve member to overcome the urge of the inlet valvespring and to unseat the inlet valve, a flat on the cam enabling thevalves to remain set in this position, the thrust of the inlet valvespring on the inlet valve member employing the thrust plate as a leverpivoted at its point of contact on the cam to further urge the exhaustvalve member into seating engagement.

To maintain the valve block according to the invention at a compactsize, a further aspect of the invention comprises a lever arrangementfor operating conventional valves incorporated in the valve block. Boththese valves are normally in closed position, with a handled operatinglever to open the valves, pivoted towards the inlet valve, the leverhaving a raised portion to contact, upon rotation, the inlet valvemember, and a shaped portion to abut a correspondingly shaped portion onthe valve block, so that the lever cannot pass a dead center positionbut on release always returns, by the action of the inlet valve spring,to its neutral position. To unseat the exhaust valve the same handle isrotated but in the opposite direction and a pivoted link is arrangedbetween the lever and the exhaust valve member. The link has a raisedportion to contact the exhaust valve member and a flat portion tocontact, eventually, a flat portion on the lever but to the other sideof the lever pivot than the lever raised portion. When these flats arein contact the exhaust valve is fully open and the lever and link willremain set in this position until the lever is moved back to its neutralposition.

The invention will now be further described, by way of example, withreference to the accompanying drawings in which:

FIG. 1 is a sectional view through a valve block of a pair of inlet andexhaust valves incorporating one embodiment of the invention;

FlG. 2 shows schematically the arrangement of FIG. 1;

FlG. 3 is a plan view of a valve block according to a second embodimentof the invention showing four pairs of inlet and exhaust valves;

FIG. 4 is a vertical cross section on the line lV-lV of FIG. 3;

FIG. 5 is a vertical cross section on the line V-V of HG. 3;

FlG. 6 is a partial section on the line Vl-Vl of FIG. 3, and

FIG. 7 is also a section on the line Vl Vl of FIG. 3, but showing adifferent position.

In FIGS. 1 and 2, a valve block 1 has attached thereto, by bolts (notshown) a cam box 2, the valve block containing axially displaceableinlet and exhaust valves indicated generally at 3 and 4, respectively.

The inlet valve 3 consists of a conical valve member 5 normally urgedinto seating engagement with a valve seat 6 by a spring 7 bearing,through a guide 8, on the upper end of the valve member 5, the valvebeing provided with suitably ar ranged seals 9. The spring 7 is housedin a cover 10 which screws into the valve block, the spring pressurebeing adjustable by this means.

Similarly, the exhaust valve 4 consists of aconical valve member 11normally urged out of seating engagement with a valve seat 12 by aspring 13, the valve seat 12 being movable against the urge of a spring14. A cover 15 surrounds both springs and screws into the valve block.

With the valve block controlling the advancing ram of a powered roofsupport, two pairs of valves according to the invention one for thepull" side and one for the push side of the ram --are controlled by acam 16 mounted on a spindle l7 projecting from the cam box 2. The camacts through hardened steel balls 18. Referring now specifically to H6.2, an inlet 19 allows pressure fluid to enter the chamber occupied byvalve member 5, and upon the face cam 16 being appropriately rotated,the valve member 5 is urged away from its valve seat 9 against the forceof its biassing spring 7. This allows fluid to flow through crossporting 20, and then through porting 20A and to the ram, because at thesame time but preferably slightly in advance of the opening of the valve3, the cam 16 also effects closing of the valve 4, the valve member 11moving upwardly to position 11A. With valve member 11 in its normallyopen position fluid can then flow via portings 20A and 21 to exhaust.

The second embodiment of the invention illustrated in FIGS. 3 to 7 willnow be described. Parts corresponding to parts of the first embodimenthave been given like reference numerals.

As shown in FIG. 4 pivotally mounted between four sets of verticallyextending ribs 22 are cams 23. The cam acts through a loose thrust plate24 onto both inlet and exhaust valve members. When the cam is rotated,its displaced axis of rotation and the different spring ratings meanthat the end 25 of the plate contacting the exhaust valve member isdisplaced before the end 26 of the plate contacting the inlet valve, thelatter end of the thrust plate only being displaceable when the exhaustvalve end 27 is arrested by seating of the exhaust valve member. Then,the thrust plate 24, under the force put on it by the cam 23, pivotsabout its point of contact 27 with the exhaust valve member to overcomethe urge of the inlet valve spring 7 and to unseat the inlet valve, aflat 28 on the cam enabling the valves to remain set in this position,the thrust of the inlet valve spring 7 on the inlet valve memberemploying the thrust plate 24 as a lever pivoted at its point of contact29 on the cam to further urge the exhaust valve member 11 into seatingengagement. Thus the normally open exhaust valve 4 is closed before theopening of the inlet valve 3.

As shown in FIG. 5, pivotally mounted between four sets of verticallyextending ribs 22 are handled cam levers 30 to open the valves, pivotedtowards the inlet valve 4, the lever having a raised portion 31 tocontact, upon rotation, the inlet valve member, and a shaped portion 32to abut a correspondingly shaped portion 33 on the valve block I, sothat the lever cannot pass a dead center position but on release alwaysreturns, by the action of the inlet valve spring 7, to its neutralposition which is the position illustrated. To unseat the exhaust valvethe same handle is rotated but in the opposite direction and a pivotedlink 34 is arranged between the lever and the exhaust valve member. Thelink has a raised portion 35 to contact the exhaust valve member and aflat portion 36 to contact, eventually, a flat portion 37 on the leverbut to the other side of the lever pivot 38 than the lever raisedportion 31. When these flats are in contact the exhaust valve 4 is fullyopen and the lever and link will remain set in this position until thelever is moved back to its neutral position.

n returning the lever 30 to the neutral position i.e. that shown in FIG.I, valve spring 7 will automatically close the valve. To operate theother chock the second lever 34 is operated.

With the valves of FIG. controlling e.g. one of the chocks of a poweredroof support by moving all levers 30 together all the chocks controlledthereby will operate simultaneously.

According to a further feature of the invention, illustrated in FIGS. 6and 7, the valve block may have either a single exhaust connection or adouble exhaust connection.

Considering again the valve block applied to an underground powered roofsupport on a single exhaust connection system both the chocks and theadvancing rams exhaust into one exhaust main. This system hasdisadvantages if a fast gravity lowering of the chocks is required sincewhilst the chocks of one support are lowering the rams of supportsfurther along the face would be operating and would be forciblyexhausting into the same exhaust main. This forced exhausting from theadvancing rams tends to cause a back pressure at the chock exhaust thuspreventing them from lowering. To overcome this difficulty, theinvention in this aspect provides that the chocks are put onto anexhaust main separate from that of the rams.

This system of exhaust is achieved by interconnecting the lower chambersof all the exhaust valves by suitable cross portings 43 and 44 (FIG. 3)the outer ends of each porting being tapped to take an adapter 45 or aplug 46. A vertical bore 48 is then drilled between the two center-chockand ram valves to intersect porting 43 as shown in FIGS. 6 and 7. Thebore 48 is threaded at its outer end. A plug 49 having an O- ring seal50 is then screwed into the bore 48.

With the plug 49 in the position shown in FIG. 7 i.e. not closing theporting 43 and a plug 46 screwed into porting 44 then both chocks andrams exhaust through porting 43 and adapter 45, i.e. a single exhaustconnection.

But by screwing plug 49 to the bottom of its travel and thus blockingporting 43 (as shown in FIG. 6) and replacing plug 46 with anotheradapter 45, then the checks will exhaust through porting 44 and the ramsthrough porting 43, i.e. a double-exhaust connection.

The pressure bore through the valve body for the four inlet valves i.e.those to the left hand side of FIG. 3 may be drilled completely throughthe valve block to provide a single working pressure for a plurality ofvalves. Alternatively the single bore may be replaced by two bores 41,42 drilled from either side of the valve block but both leaving a solidbody between the two bores thus producing a two-pressure system. This isshown in FIG. 3 with 3 valves on the bore 42 and one valve on the bore41. Alternatively two valves could be arranged on each bore.

The valve block as illustrated in FIG. 3 is additionally provided withcheck valves 39 and 40.

A pair of plugs at each of the bores 41, 42 contain a nonreturn valve towhich access may be gained by removing the cap of the plug, are providedin the valve block I. These prevent escape of pressure fluid from theinterior of the valve block but allow a pressure auge to be screwed inin order that the pressure in the valve b ock may be monitored. Twovalves are provided, one to allow monitoring of the pressure of eachchock. By inserting the spigot of a proprietory form of pressure gaugethe normally closed nonretum valve is opened to allow testing of theinternal pressure in the valve block.

Iclaim:

l. A valve assembly comprising a valve block having first and secondparallel bores therein, an inlet valve, an exhaust valve, said firstparallel bore housing only said inlet valve and said second parallelbore housing'only said exhaust valve, an inlet valve spring acting tourge said inlet valve, normally, into closed position, anexhaust valvespring acting to urge said exhaustvalve, normally, into open position,and cam means coupled to said inlet and exhaust valves functioning firstto displace mechanically said exhaust valve against said exhaust valvespring into closed position, and subsequently to displace mechanicallysaid inlet valve into open position.

2. A valve block as in Claim 1, wherein the exhaust valve has a fixedvalve seat and is displaceable into engagement therewith by means of acam pivoted slightly towards the exhaust valve from the inlet ,valve'ofthe pair, with the exhaust valve spring lighter than the inlet valvespring and a loose and rockable thrust plate located between the cam andboth the inlet and exhaust valve members.

3. A valve block as in claim 1 containing conventional valves bothnormally open, a handled operating lever to open the valves separatingthe latter the liner being pivoted towards the inlet ,valve and having araised portion to contact, upon rotation, the inlet valve member, and ashaped portion to abut a correspondingly shaped portion on the valveblock.

4. A valve block as in claim 3 comprising a pivoted link having a raisedportion to contact the exhaust valve member, and a flat face to contacta flat face on the lever.

5. A valveblock provided with two pairs of valves as defined in claim Iand with two pairs of conventional valves, both the latter normallyclosed.

6. A valve block as in claim 5, wherein the pressure bore is constitutedby two bores drilled from opposite sides of the block to provide atwopressure system.

7. A valve block as in claim 5 comprising cross portings eachassociated-with at least one exhaust valve, one of the cross portingsbeing intersected by a bore, an adjustable screwed plug located in thebore serving, in one position, to allow connection of thecross ports,and in another position, to prevent such connection.

1. A valve assembly comprising a valve block having first and secondparallel bores therein, an inlet valve, an exhaust valve, said firstparallel bore housing only said inlet valve and said second parallelbore housing only said exhaust valve, an inlet valve spring acting tourge said inlet valve, normally, into closed position, an exhaust valvespring acting to urge said exhaust valve, normally, into open position,and cam means coupled to said inlet and exhaust valves functioning firstto displace Mechanically said exhaust valve against said exhaust valvespring into closed position, and subsequently to displace mechanicallysaid inlet valve into open position.
 2. A valve block as in Claim 1,wherein the exhaust valve has a fixed valve seat and is displaceableinto engagement therewith by means of a cam pivoted slightly towards theexhaust valve from the inlet valve of the pair, with the exhaust valvespring lighter than the inlet valve spring and a loose and rockablethrust plate located between the cam and both the inlet and exhaustvalve members.
 3. A valve block as in claim 1 containing conventionalvalves both normally open, a handled operating lever to open the valvesseparating the latter the liner being pivoted towards the inlet valveand having a raised portion to contact, upon rotation, the inlet valvemember, and a shaped portion to abut a correspondingly shaped portion onthe valve block.
 4. A valve block as in claim 3 comprising a pivotedlink having a raised portion to contact the exhaust valve member, and aflat face to contact a flat face on the lever.
 5. A valve block providedwith two pairs of valves as defined in claim 1 and with two pairs ofconventional valves, both the latter normally closed.
 6. A valve blockas in claim 5, wherein the pressure bore is constituted by two boresdrilled from opposite sides of the block to provide a two-pressuresystem.
 7. A valve block as in claim 5 comprising cross portings eachassociated with at least one exhaust valve, one of the cross portingsbeing intersected by a bore, an adjustable screwed plug located in thebore serving, in one position, to allow connection of the cross ports,and in another position, to prevent such connection.